This invention pertains to display systems and more particularly to display systems which display symbols formed by assembling rows of indicia.
One of the most common types of symbol display systems utilizes a device which scans a record medium with a horizontal line raster such as used in commercial television. The most typical of such display systems employs a cathode ray tube wherein a beam of electrons is intensity modulated while raster scanning the phosphor coated face of the tube. Other display systems can use a laser or other light source as the source beam and a xerographic drum or photographic film as the record medium. Non-radiation type sytems use ink jets aimed at a paper record medium. In any of these display systems the symbols are formed by either generating adjacent lines of varying length or more commonly by assembling arrays of rows of dots to form a dot matrix.
Typically in such systems a memory stores a representation of the dot matrix for each symbol to be displayed. Thus for example if a symbol is represented by suitable dots in a 8.times.16 matrix and there are 128 symbols to the font considerable memory space is required. When foreign language fonts having characters with diacritical marks, or fonts having underlinable symbols or fonts having superscripts, subscripts and the like are used the memory size also increases.